Hello there, i am selling project --> RFID stopwatch with Arduino uno and RFID reader, LCD display, buzzer, relays.It works with 2 times and it is for extreme games like airsoft/paintball/nerf wars for mode King of The hill. Each time collect time for time, that they are on hill. Each member of time have rfid keychain, after he put it on rfid reader (13.56MHz) it will start time of his team and another team's time will be stopped.

There are 2 types of special keychains. 1. organisator, that will pause both times2. Eraser, that erase time to 00:00:00